Coupling

ABSTRACT

A coupling half designed to mate with an identical coupling half to form a coupling for interconnecting sections of hose or the like, has a tubular body having at one end a projecting tooth and a complementary socket arrangement constituted by a plurality of uniformly spaced arcuate connector teeth axially outstanding from the tubular body and terminating in a radially inwardly directed arcuate protrusion, a plurality of radially outwardly directed arcuate ribs circumferentially aligned with the teeth, and a plurality of tooth entrance ways located circumferentially between each of the ribs and each of the teeth, a resiliently biased detent locking device in the body biased towards an advanced position, and an annular detent unlocking ring angularly rotatable on the body and resiliently biased in one direct ion of rotation to an inoperative position and being angularly movable in the opposite direction to an active position wherein it engages the detent locking means to retract it away from the advanced position.

BACKGROUND OF THE INVENTION

This application is a continuation-in-part of our copending U.S.Application Ser. No. 07/765,090 filed on Sep. 25, 1991, now U.S. Pat.No. 5,184,851.

The present invention relates to a coupling half for a quick-connectcoupling such as a hose coupling.

The advantages, especially for fire-fighting where time is veryimportant, of being able quickly to connect together water carryingmembers has long been known and there are several designs for couplingsthat, with one quarter turn, or less, of two interacting couplinghalves, create a watertight seal between two water carrying members suchas hoses, valves, nozzles etc. Such couplings may be said to fall withinone of two categories: 1) "male and female"; and 2) "identical",sometimes called "sexless", couplings. Identical couplings have theadvantage that any coupled end of any water carrying member may bepresented for connection to any other of the same type. The presentinvention relates to a coupling of the identical type.

There is on the market an identical coupling known as a "Storz*Coupling" in which the coupling halves each have a cam ring which isrotatable relative to the associated hose connection piece and whosecams engage in a bayonet-type locking engagement with grooves of the camring of the other respective coupling half. The grooves, which areannular in form, have a slope and the turning of the cam rings causesthe hose connection halves to draw together axially. An example of suchcoupling is seen in U.S. Pat. No. 4,524,997 issued to Ebert Jun. 25,1985. Although this general type of coupling has received wide usage itposes certain disadvantages in operation, particularly the probleminherent in all quick connect couplings--that of potential unintentionalde-coupling. De-coupling forces may arise as a result of water-pressureinduced torque or as a result of the manoeuvring of hose or otherfire-fighting equipment. With the Storz coupling, the cam rings arebuilt such that when rotationally engaging the two coupling halvesmaximum compression of the mating seals upon the face of each couplinghalf is achieved when the coupling is rotated through the first part ofit's rotational range. Thereafter, as rotation is continued to it'slimit, because the grooves of the engaging cam rings are then reversesloped, the coupling halves will move slightly away from each otheraxially and allow the seals to de-compress partially. The coupling willthen resist de-coupling by making it necessary to both compress theseals and to rotate them in opposite directions against their compressedcontact before de-coupling can take place. The disadvantage of this typeof coupling is that it is difficult to rotationally engage or disengagethe coupling halves and, of course, the larger the diameter of thecoupling the more the force which is required to engage or disengage it.This design also has the disadvantage that because all the interlockingfeatures are located on the face of the coupling they become hidden fromview once the coupling halves are engaged and initially rotated, thusthere is no visual reference to indicate whether or not any two engagedcoupling halves are fully rotated or not.

A second type of coupling is marketed by the National Fire HoseCorporation of Compton, California (J. M. Huber, manufacturer ) underthe name of Staytite* couplings, as seen in the U.S. Pat. No. 4,643,459.These couplings connect with less than a quarter turn and, when fullyrotated are automatically locked against rotation by the engagement of asix piece spring-assisted locking plug and locking slide assemblylocated in each coupling half. This design suffers from practicaldisadvantages; it is expensive to produce, there is a likelihood of partfailure, and it is difficult to repair.

U.S. Pat. No. 1,112,850, issued on Oct. 6, 1914 to Sherer, shows a hosecoupling which has sexless members with circumferentially slotted hooksfor interlocking engagement with corresponding studs. Locking pins arealso provided with this device to prevent the studs from being withdrawnfrom their corresponding hooks. The locking pins are normally urged to aprotruding position by abutment against the edge of a rotatable collarof the coupling. The rotatable collar provides a series of notches whicheffect retraction of the locking member. This device uses a threaded andunbiased collar for the couplings, an arrangement which proves to berelatively cumbersome to operate under field conditions.

U.S. Pat. No. 4,643,459 issued on Feb. 17, 1987 to Carson, discloses acoupling half with locking pins which are biased to extend outwardly ofthe coupling faces, and are retracted during coupling by a ramped end ofthe sidewall extensions. Further rotation of the coupling members thencauses each coupling pin to fall into its corresponding receptacle. Tounlock the coupling cammed circumferential slides are activated toretract the pins out of the receptacles. This arrangement proves to bedifficult to operate since the locking pins of each half are notmaintained in an extended position ready for rapid reattachment andlocking of the halves after disconnection. Furthermore, to disconnectthe coupling halves the operator must retract the locking pins in afirst movement, and then in a second movement proceed to uncouple thetwo halves of the hose coupling by relative rotation of the one to theother, making rapid disconnect ion difficult.

It is an object of the present invention to provide an improved locksystem for a quick-connect coupling. This invention is particularlydirected towards the sealable engagement of conduit members which carrypressurized water and more particularly again towards engagement ofconduit members of a large diameter which are difficult to manoeuvre andlock. No special knowledge of coupling hoses is required to use thecoupling halves of the present invention. This can be particularlyadvantageous in field conditions where untrained volunteer fire-fightersmay be used.

SUMMARY OF THE INVENTION

The invention provides a coupling half designed to mate with anidentical coupling half to form a coupling for interconnecting sectionsof hose or the like, said coupling half comprising: a tubular bodyhaving at one end a projecting tooth structure and a complimentarysocket arrangement comprising a plurality of uniformly spaced arcuateconnector teeth axially outstanding from the tubular body andterminating in a radially inwardly directed arcuate protrusion, aplurality of radially outwardly directed arcuate ribs circumferentiallyaligned with said teeth, and a plurality of tooth entrance ways locatedcircumferentially between each of said ribs and each of said teeth;detent locking means associated with said socket arrangement beingmounted in said body to be moveable towards and away from an advancedposition, and being resiliently biased towards said advanced position;detent unlocking means comprising an annular ring supported on said bodyto be angularly rotatable thereon, said ring being resiliently biased inone direction of rotation to an inoperative position and being angularlymoveable in the opposite direction to an active position wherein itengages the detent locking means to retract it away from said advancedposition; the arrangement being such that one said coupling half isconnect able to an identical coupling half by interengagement betweenthe complimentary tooth structures and socket arrangements to form thecoupling with each of said locking detent means automatically moving toits advanced position to block disengagement from the socket arrangementof the tooth structure of the opposed coupling half; disengagement ofthe two coupling halves requiring angular rotation of each of saidannular rings in opposite direct ions.

The invention also provides a coupling half designed to mate with anidentical coupling half to form a coupling for interconnecting sectionsof hose or the like, said coupling half comprising: a tubular bodyhaving at one end a projecting tooth structure and a complimentarysocket arrangement comprising a plurality of uniformly spaced arcuateconnector teeth axially outstanding from the tubular body andterminating in a radially inwardly directed arcuate protrusion, aplurality of radially outwardly directed arcuate ribs circumferentiallyaligned with said teeth, and a plurality of tooth entrance ways locatedcircumferentially between each of said ribs and each of said teeth;detent locking means associated with said socket arrangement beingmounted in said body to be moveable towards and away from an advancedposition and a means for moving said detent locking means toward theadvanced position; detent unlocking means comprising an annular ringsupported on said body to be angularly rotatable thereon, said ringbeing resiliently biased in one direction of rotation to an inoperativeposition and being angularly moveable in the opposite direction to anactive position wherein it engages the detent locking means to retractit away from said advanced position; the arrangement being such that onesaid coupling half is connect able to an identical coupling half byinterengagement between the complimentary tooth structures and socketarrangements to form the coupling with each of said locking detent meansautomatically moving to its advanced position to block disengagementfrom the socket arrangement of the tooth structure of the opposedcoupling half; disengagement of the two coupling halves requiringangular rotation of each of said annular rings in opposite directions.

In one particularly useful embodiment of this invention the detentlocking means is preferably provided by an upwardly biased locking tabsupported in the outer periphery of the coupling half, and operable whenthe two coupling halves are coupled to automatically engage behind thetrailing edge of the projecting tooth of the opposing coupling half. Thelocking tab is also provided with a ramp face which is in operativecommunication with the detent unlocking means such that when thecoupling halves are in a coupled position, the annular rings of thedetent unlocking means can be rotated such that inclined faces on theinterior of the rings cooperatively engage the inclined tab faces so asto withdraw the tabs and permit relative uncoupling rotation of the twocoupling halves.

In another particularly useful embodiment of this invention the detentlocking means is preferably provided by an upwardly biased locking pinsupported in at least one of the connector teeth and operable when thetwo coupling halves are coupled to automatically engage an aperture inthe complimentary socket of the opposing coupling half.

BRIEF DESCRIPTION OF THE DRAWINGS

The following is a description, by way of example, of the preferredembodiments of the present invention, reference being had to theaccompanying drawings in which:

FIG. 1 is a partially sectioned side view of the first embodiment of onecoupling half;

FIG. 2 is a plan view of that coupling half;

FIG. 3 is a perspective view of the coupling half;

FIG. 3a is a detailed perspective view, partly in section, of thecoupling half locking tab and collar;

FIG. 4 is a sectional view taken on the lines IV--IV of FIG. 2;

FIG. 5 is a side view of two coupling halves assembled into thecoupling;

FIG. 6 is a plan view which shows a three-piece clamp ring whichsurrounds the base of the coupling half;

FIG. 7 is a sectional side view taken on the line VII--VII of FIG. 8 ofa release collar of the coupling half;

FIG. 8 is a top plan view of the collar illustrated in FIG. 7;

FIG. 9 is a bottom plan view of the collar illustrated in FIG. 7;

FIG. 10 is a perspective view of a modified form of the coupling half asshown in FIG. 1;

FIG. 11 is a plan view of the coupling shown in FIG. 10;

FIG. 12 is a sectional view taken on the lines XII--XII of FIG. 11showing a locking pin;

FIG. 13 is a bottom plan view of the coupling shown in FIG. 10 with theclamping ring removed;

FIG. 14 is a detailed perspective view, partly in section, of thecoupling half shown in FIG. 10, showing the locking pin and collar;

FIG. 15 is a side view of two coupling halves shown in FIG. 10 assembledinto the coupling; and

FIG. 16 is a detailed view of the locking pin shown in FIG. 12.

DESCRIPTION OF THE PREFERRED EMBODIMENT

As is illustrated in FIGS. 5 and 15, a coupling 10 is formed of twoidentical coupling halves 11a and 11b. Each coupling half (see FIGS. 4and 12) is formed from a generally tubular body 12 with a smoothly boredinterior 13. The tubular body is preferably cast or machined from alightweight material such as aluminum.

In a first embodiment, at the top portion of the body 12 the perimeterof bore 13 is surrounded by an annular top face 16 having a groovedchannel 14 into which a resilient seal 15 is placed. Extending axiallyfrom the face 16 of the body 12 are two opposed arcuate connector teeth17 which are of a generally inverted "L-shape" in profile. The top limb18 and side limb 19 of each inverted "L-shaped" tooth 17, together withface 16, define an arcuate tapered groove 20, as best seen in FIGS. 1, 3and 4, which tapers in height along the tooth from what hereinafter isreferred to as the leading end 17a to the trailing end 17b of the tooth17. Circumferentially aligned and spaced below and radially inwardly ofeach tooth 17, the sidewall 22 of body 12 carries two outwardly directedarcuate flange-like ribs 21. Spaced below the teeth 17 and surroundingthe side wall 22 of the body 12 there is an integral collar 23 with anupper face 23a. The ribs 21, together with the side wall 22 and face 23adefine a second tapered groove 24 which tapers in height from theleading end 21a of rib 21. A pair of arcuate tooth entrance ways 25 areeach defined by a circumferential gap, of a generally lesser arc thanthe connector teeth 17, between the leading end 21a of rib 21 and thetrailing end of the opposed tooth 17.

In a plane normal to the longitudinal axis 26 (FIG. 2) of the couplinghalf 11 the arcuate connector teeth 17 each subtend an angle of about62°, the arcuate ribs 18 each subtend and angle of about 53° and theentrance ways 25 each subtend an angle of about 65°.

The bottom portion of body 12 (see FIG. 4) has a cylindrical surface 27which receives the end of a flexible hose 28 and is formed with a seriesof grooves 27a which co-operate with corresponding ribs 29 of athree-piece surrounding clamping ring 30 (see FIG. 6) to affix the hoseto the body and to form a leak proof connection. The three pieces of theclamping ring 30 are releasably connected by recessed capscrews 31 whichalso permit the ring to be adjusted to accept different thicknesses ofhose to be attached over the bottom portion of the body 12.

On the outer periphery of body 12 there are a pair of recessed axialchannel guides 33 which open from the face 23a of integral collar 23 andwhich are each located within one of the entrance ways 25, between theleading end of arcuate rib 21 and opposed tooth 17. A locking tab 32 iscarried on a generally rectangular body 34 and is mounted in eachchannel guide 33. The tab 32 has a smoothly rounded tailing edge 35 andis of generally the same thickness as integral collar 23. Extendingoutwards from the tab 32 the rectangular body has a ramp face 36 thatslopes upwardly, as best seen in FIG. 3a. The tab 32 is movable in theaxial direction within the channel guide 33 and is upwardly biased by acompression spring 37 which is placed between the bottom wall of channelguide 33 and the bottom of body 34.

Surrounding the outer periphery of the middle portion of body 12 andadjacent the ring 30 and the integral collar 23 is an annular ring thatforms a rotatable collar 38. The collar 38 is preferably made from aplastic or similar material. As best seen in FIGS. 3a and 7 to 9 thecollar 38 has two diametrically opposed cavities 39 opening from itsinner cylindrical surface and each receiving one of said tabs 32 withclearance so as to permit limited angular movement of the collar 38circumferentially around the body 12 and between what will hereinafterbe referred to as an inoperative position and an operative position.Within each cavity is a tension spring 40 connected at one end to a pin41 formed on collar 38 and at the other to a pin 42 located adjacent thecorresponding channel guide 33 on body 12. The spring 40 resilientlybiases the collar 38 in the inoperative position. Each cavity opens tothe top face of the collar 38 through a slot 43 that is aligned radiallywith the upper edge of ramp face 36. In each cavity 39 there is aninclined collar ramp face 44 (FIG. 1) which extends from the edge ofslot 43 to oppose and cooperate with ramp face 36. The arrangement ofthe faces 36 and 44 is such that their lower edges overlap slightly inthe operative position.

In order to quick connect the two coupling halves 11a and 11b they areplaced in axially aligned position with the teeth 17 of each couplinghalf facing the entrance ways 25 of the opposing coupling half. As thetwo coupling halves are moved axially together, the teeth 17 initiallymove into the entrance 10 ways 25 and then meet and depress the lockingtabs 32. The two coupling halves may then be rotated relative to oneanother. Initially there is clearance between the leading edge of tooth17 and the leading edge of the opposed rib 21. As rotation of thecoupling halves is continued toward the fully engaged position, theclearance narrows and faces 18a and 21a engage, drawing the two couplinghalves axially together. In the process the seals 15 provided in channel14 of each coupling half are compressed against one another. In this waythe teeth 17, entrance ways 25 and ribs 29 of the two coupling halvesform a tooth and complimentary socket arrangement.

As the two coupling halves are rotated to the fully engaged position, inapproximately one sixth of a turn, the trailing ends of the teeth 17pass over the locking tabs 32, which are then released and able to moveupwardly under the force of spring 37 to an active (advanced) positionso as to automatically engage behind the trailing end of the associatedconnector tooth 17 of the opposing coupling half as seen in FIG. 5. Thisprovides a type of locking detent which locks the coupling halves in theengaged position and prevents them from rotating to unlock. The operatormay be sure that the two coupling halves are locked since the tabs 32are clearly visible when in the advanced position, and also make anaudible "click" sound when engaging.

In order to disconnect the two coupling halves 11a and 11b the tabs 32are retracted to an inactive position by rotating each of the collars 38from the inoperative to the operative position. As the collar 38 isrotated, the inclined collar face 44 fully engages with the face 36,rides over it, and pushes the tab 32 down the channel guide 33 with acamming motion. This provides a type of detent unlocking means. Once thelocking tabs 32 of each coupling half are retracted, it is possible tounlock the two coupling halves by rotating the coupling halves bycontinuing the rotational force upon the collars, since when each collarreaches its full extent of t ravel in the operative position, therotational force applied to each collar is then transferred to thecoupling half. Furthermore, as the collar is resiliently biased by meansof spring 40, when the collar is released it returns to the inoperativeposition with the locking tabs 32 biased upwardly, in the activeposition, ready for rapid re-engagement with a second coupling half.

In the embodiment of the invention illustrated in FIGS. 10 to 16 certainof the structural components are the same or substantially the same, asthose previously described and are indicated by the same referencenumerals. In this modification two opposed arcuate connector teeth 117,extend axially from the face 16 of body 12. The connector teeth 117 areagain of a generally inverted "L-shape" in profile and comprise top limb118 and side limb 119 and which together with face 16 define an arcuatetapered groove 120, as best seen in FIG. 10, which tapers in heightalong the tooth from the leading end 117a to the trailing end 117b oftooth 117. However, the groove 120 is closed at the trailing end 117b bylimb 50 and a headed locking pin 52 is carried by one tooth 117 on topof limb 118 at the trailing end 117b. Spaced below the teeth 117 andsurrounding the side wall 22 of body 12 the upper face 123a of integralcollar 23 has an aperture 54 at approximately the mid-point between thetrailing end 117b of one tooth and the leading end 117a of the other.

The locking head 56 of locking pin 52 is carried on a shaft 58 and isgenerally cylindrical with rounded corners on its outer periphery and isof generally lesser diameter than aperture 54 on the upper face 123a toreceive locking pin 52.

The locking head 56 on shaft 58 is guided for axial sliding movement ina guideway such as bore 60 drilled or otherwise provided in the bottomend of side limb 118 of tooth 117, as best seen in FIGS. 12 and 16.Counterbore 62 formed in the tooth 117 from the top end of limb 118receive a compression spring 64 which embrace the shaft 58 of lockingpin 52 and is confined between the radial shoulder 66 at the end of thecounterbore 62 and shoulder 68 on locking head 56 of locking pin 52. Thelocking head 56 of locking pin 52 is upwardly biased by the compressionspring 64 and projects above tooth 117, while the shaft 58 projectsbelow the tooth and carries a collet 70 held in place by split retainingring 72 seated on shaft 58. Locking pin 52 has a sliding fit in thecounterbore 62 to guide the axial movement of the pin.

Surrounding the outer periphery of the middle portion of body 12,between integral ring 23 and ring 30, is an annular ring that forms arotatable collar 138. As best seen in FIGS. 12, 13, and 14, the collar138 has a slot 74 and a cavity 76 within its inner cylindrical surface.The slot 74 is a generally elongate oval and receives shaft 58 withclearance so as to permit limited angular movement of the collar 138circumferentially around the body 12 and between the inoperative andoperative positions. Formed within slot 74 there is an inclined rampshoulder 78 which surrounds shaft 58 to oppose and co-operate with stud70 mounted on the shaft 58. In cavity 76 there is a tension spring 80which is fastened to the wall of the collar 138 and a lug 82 on theperiphery of body 12 to resiliently bias the collar 138 in theinoperative position. When ring 30 is removed, the slot 74 and cavity 76are accessible through access plate 84 which is held in place by screws86, as best seen in FIG. 13.

The two coupling halves are engaged for coupling as previouslydescribed, or substantially so. In this embodiment, however, as the twocoupling halves 11a and 11b are moved axially together, the locking pins52 of each half which are carried on teeth 117 meet with the face 123aand are depressed into the counterbore 62. The two coup-ling halves maythen be rotated one to the other as previously described. As the twocoupling halves are rotated to the fully engaged position, inapproximately one sixth of a turn, the locking heads 56, carried on thetrailing end of teeth 117b pass along faces 123a and the locking pinswill come into register with the apertures 54 so that the springs 64will automatically urge the pins 52 and locking heads 56 into theapertures 54 to an active (advanced) position. This again provides atype of locking detent which locks the coupling halves in the engagedposition and prevents them from rotating to unlock. The operator may besure that the two coupling halves are locked since there is an audible"click" sound.

In order to disconnect the two coupling halves 11a and 11b of thisembodiment, the locking heads 56 are retracted to an inactive positionby rotating each of the collars 138 from the inoperative to theoperative position. As the collar 138 is rotated, the inclined rampshoulder 78 engages the stud 70 which rides along the shoulder and pullsshaft 58 of pin 52, and thus head 56, into the counterbore in tooth 117with a camming motion. This provides a type of detent unlocking means.Once the locking heads 56 of each coupling half are retracted, it ispossible to unlock the two coupling halves as previously described.Again, because the collar is resiliently biased by means of spring 80,when the collar is released it returns to the inoperative position withthe locking head 68 biased upwardly, in the active position, ready forrapid re-engagement with a second coupling half.

As each of the two coupling halves of the embodiments described aboveare identical, when joined it is necessary to simultaneously exertrotational force upon each collar in an opposite direction. This type ofarrangement is particularly useful in situations where a coupled hose isto be manoeuvred across the ground, by pulling it, since the tendency touncouple due to external forces is minimized. This is because anyfrictional motion which might cause one of the collars to rotate, andthus retract one locking tab or locking pin, as the case may be, wouldsimultaneously exert an opposite effect on the opposed collar.

As shown and described in the first embodiment there are two teeth 17,two entrance ways 25, two ribs 29, and two tabs 32 on each coupling half11a and 11b. However, the coupling and locking system would functionequally as well if only one tab 32 were provided on each coupling half11a and 11b, or if a different number of teeth 17, entrance ways 25 andribs 29 were used.

Again, as shown and described in a second embodiment there is onelocking head 60 on each coupling half 11a and 11b. However, it will beunderstood that the coupling and locking system would function equallyas well with two locking heads 56 on each half 11a and 11b, or, asabove, if a different number of teeth 117, entrance ways 25 and ribs 29were used.

What I claim as my invention:
 1. A coupling comprising two complementarycoupling halves designed to mate with one another for interconnectingsections of hose, each said coupling half comprising:a tubular bodyhaving at one end a projecting tooth structure comprising a plurality ofuniformly spaced arcuate connector teeth axially outstanding from thetubular body and terminating in a radially directed arcuate protrusion,and a corresponding socket arrangement comprising a correspondingplurality of arcuate ribs directed in the opposite radial direction tosaid protrusions at a radius corresponding to that of said teeth, and aplurality of tooth entrance ways located circumferentially between eachof said ribs and one of said teeth; detent locking means associated withsaid socket arrangement being mounted in said body to be moveabletowards and away from an advanced position, and means for moving saiddetent locking means towards said advanced position; detent unlockingmeans carried by said body being manually moveable from an inoperativeposition to an operative position, said unlocking means upon movementthereof to said operative position being adapted to engage with withdrawsaid detent locking means from its advanced position; wherein saiddetent locking means comprises an axially outwardly resiliently biasedlocking pin supported in one said connector tooth and operable toautomatically engage a complementary aperture in the socket of the othercoupling half when said pin is moved into register with such aperture,when the two coupling halves are joined; and wherein said detentunlocking means comprises an annular ring supported on and extendingaround the circumference of said body to be angularly rotatable thereon,said ring being resiliently biased in one direction of rotation towardssaid inoperative position; the arrangement being such that one saidcoupling half is connectable in axial alignment to the other couplinghalf be juxtaposition and interengagement between the complementarytooth structures and socket arrangements thereof to form the coupling,with each of said locking detent means being automatically moved to itsadvanced position once make-up of the coupling has been completed toblock disengagement from the associated socket arrangement of the toothstructure of the opposed coupling half; disengagement of the twocoupling halves requiring angular rotation of said two annular rings inopposite directions to withdraw said detent locking means of eachcoupling half.
 2. A coupling according to claim 1 wherein each couplinghalf has two connector teeth, two entrance ways and two arcuate ribs,each arcuate rib and each arcuate protrusion being tapered so that theaxial thickness thereof increases from a leading end to a trailing end,and wherein at the coupling longitudinal axis, and viewed in a planenormal thereto, each arcuate connector tooth subtends an angle of about62°, each arcuate rib subtends an angle of about 53°, and each of saidentrance ways subtends an angle of about 65°.
 3. A coupling as claimedin claim 1 wherein each locking pin has a shaft in operativecommunication with the associated detent unlocking means such that withthe coupling halves in the joined position, when each annular ring ofthe detent unlocking means is rotated to its operative position, theassociated locking pins are withdrawn to permit relative uncouplingrotation of the coupling halves to be effected through manual engagementand rotation of said annular rings.
 4. A coupling as claimed in claim 3wherein each annular ring of the detent unlocking means is provided withan inclined ramp shoulder to cooperatively engage the associated lockingpin when the annular ring is rotated.
 5. A coupling as claimed in claim4 wherein the locking pin has a smoothly rounded head that is slidablyreceived in an axially extending counterbore in said body said headdefining a shoulder adjacent the shaft, said shoulder forming a seat forone end of a compression spring that surrounds the shaft within saidcounterbore and urges said locking pin towards its advanced position.